Not sure of the diagnosis, but you can just cut off the worst leaves and let it grow. Sometimes those are just sunburned spots. Tomatoes can still grow and produce fruit with some funky leaves. It's rare to have everything all perfect.

Here is a link that might be useful: What's Growing On?

Clickable link:
https://www.dropbox.com/sh/icdq5revujo05te/2588XZvxkn?lst#/

Hi RemoteDoc,

I can't tell whether it's Early Blight or Septoria, but, in either case, I recommend you pick off (and throw away) all infected leaves. Then start a regular (once every 1-2 weeks) spraying program with Daconil (AKA Ortho Garden Disease Control, amongst other brands). This will not cure the disease, but will help keep it from spreading. Also, if your plants are not mulched, you should mulch them very soon. Both of these leaf diseases are very common. With care, your plants will survive and produce a good crop. Good luck!

Thanks for everyone's input. I have trimmed all leaves I thought were infected today. It looks greener and less infected, that's for sure, but it also looks more bare! :) I will keep an eye on it, and even getting some Daconil as mentioned. Thanks again for the help!